HI.

When you changed the head did you change it complete with
cam followers, cam and valves, or stripped yours if you used your parts
did you keep the cam followers in order to the cam lobes for your cams
or put in any new followers, if so did you run the cam in to them.
and the valve timing the lug you used is the edge of the lug to the
pointer left part of lug. ps before u strip it again? do a compression test.
and what is your oil pressure like as you have new bearings,should be good if pump is ok.
maybe the bearings are the wrong size.for the crank mains or bigends.
Dave.